allow links to send multiple packets at once, currently we still only bother to send 1 at a time from the switch level

src/yggdrasil/link.go

@@ -37,7 +37,7 @@ type linkInfo struct {
 
 type linkInterfaceMsgIO interface {
 	readMsg() ([]byte, error)
-	writeMsg([]byte) (int, error)
+	writeMsgs([][]byte) (int, error)
 	close() error
 	// These are temporary workarounds to stream semantics
 	_sendMetaBytes([]byte) error
@@ -207,11 +207,11 @@ func (intf *linkInterface) handler() error {
 		intf.link.core.peers.removePeer(intf.peer.port)
 	}()
 	// Finish setting up the peer struct
-	out := make(chan []byte, 1)
+	out := make(chan [][]byte, 1)
 	defer close(out)
-	intf.peer.out = func(msg []byte) {
+	intf.peer.out = func(msgs [][]byte) {
 		defer func() { recover() }()
-		out <- msg
+		out <- msgs
 	}
 	intf.peer.linkOut = make(chan []byte, 1)
 	themAddr := address.AddrForNodeID(crypto.GetNodeID(&intf.info.box))
@@ -234,12 +234,12 @@ func (intf *linkInterface) handler() error {
 		interval := 4 * time.Second
 		tcpTimer := time.NewTimer(interval) // used for backwards compat with old tcp
 		defer util.TimerStop(tcpTimer)
-		send := func(bs []byte) {
+		send := func(bss [][]byte) {
 			sendBlocked.Reset(time.Second)
-			intf.msgIO.writeMsg(bs)
+			size, _ := intf.msgIO.writeMsgs(bss)
 			util.TimerStop(sendBlocked)
 			select {
-			case signalSent <- len(bs) > 0:
+			case signalSent <- size > 0:
 			default:
 			}
 		}
@@ -247,7 +247,7 @@ func (intf *linkInterface) handler() error {
 			// First try to send any link protocol traffic
 			select {
 			case msg := <-intf.peer.linkOut:
-				send(msg)
+				send([][]byte{msg})
 				continue
 			default:
 			}
@@ -259,19 +259,21 @@ func (intf *linkInterface) handler() error {
 			case <-tcpTimer.C:
 				intf.link.core.log.Tracef("Sending (legacy) keep-alive to %s: %s, source %s",
 					strings.ToUpper(intf.info.linkType), themString, intf.info.local)
-				send(nil)
+				send([][]byte{nil})
 			case <-sendAck:
 				intf.link.core.log.Tracef("Sending ack to %s: %s, source %s",
 					strings.ToUpper(intf.info.linkType), themString, intf.info.local)
-				send(nil)
+				send([][]byte{nil})
 			case msg := <-intf.peer.linkOut:
-				send(msg)
-			case msg, ok := <-out:
+				send([][]byte{msg})
+			case msgs, ok := <-out:
 				if !ok {
 					return
 				}
-				send(msg)
+				send(msgs)
+				for _, msg := range msgs {
 					util.PutBytes(msg)
+				}
 				select {
 				case signalReady <- struct{}{}:
 				default:

src/yggdrasil/peer.go

@@ -109,7 +109,7 @@ type peer struct {
 	linkOut    (chan []byte)   // used for protocol traffic (to bypass queues)
 	doSend     (chan struct{}) // tell the linkLoop to send a switchMsg
 	dinfo      (chan *dhtInfo) // used to keep the DHT working
-	out        func([]byte)    // Set up by whatever created the peers struct, used to send packets to other nodes
+	out        func([][]byte)  // Set up by whatever created the peers struct, used to send packets to other nodes
 	close      func()          // Called when a peer is removed, to close the underlying connection, or via admin api
 }
 
@@ -250,11 +250,15 @@ func (p *peer) handleTraffic(packet []byte, pTypeLen int) {
 }
 
 // This just calls p.out(packet) for now.
-func (p *peer) sendPacket(packet []byte) {
+func (p *peer) sendPackets(packets [][]byte) {
 	// Is there ever a case where something more complicated is needed?
 	// What if p.out blocks?
-	atomic.AddUint64(&p.bytesSent, uint64(len(packet)))
-	p.out(packet)
+	var size int
+	for _, packet := range packets {
+		size += len(packet)
+	}
+	atomic.AddUint64(&p.bytesSent, uint64(size))
+	p.out(packets)
 }
 
 // This wraps the packet in the inner (ephemeral) and outer (permanent) crypto layers.

src/yggdrasil/router.go

@@ -39,7 +39,7 @@ type router struct {
 	reconfigure chan chan error
 	addr        address.Address
 	subnet      address.Subnet
-	in          <-chan []byte // packets we received from the network, link to peer's "out"
+	in          <-chan [][]byte // packets we received from the network, link to peer's "out"
 	out         func([]byte)    // packets we're sending to the network, link to peer's "in"
 	reset       chan struct{}   // signal that coords changed (re-init sessions/dht)
 	admin       chan func()     // pass a lambda for the admin socket to query stuff
@@ -52,7 +52,7 @@ func (r *router) init(core *Core) {
 	r.reconfigure = make(chan chan error, 1)
 	r.addr = *address.AddrForNodeID(&r.core.dht.nodeID)
 	r.subnet = *address.SubnetForNodeID(&r.core.dht.nodeID)
-	in := make(chan []byte, 1) // TODO something better than this...
+	in := make(chan [][]byte, 1) // TODO something better than this...
 	self := linkInterface{
 		name: "(self)",
 		info: linkInfo{
@@ -62,7 +62,7 @@ func (r *router) init(core *Core) {
 		},
 	}
 	p := r.core.peers.newPeer(&r.core.boxPub, &r.core.sigPub, &crypto.BoxSharedKey{}, &self, nil)
-	p.out = func(packet []byte) { in <- packet }
+	p.out = func(packets [][]byte) { in <- packets }
 	r.in = in
 	out := make(chan []byte, 32)
 	go func() {
@@ -114,8 +114,10 @@ func (r *router) mainLoop() {
 	defer ticker.Stop()
 	for {
 		select {
-		case p := <-r.in:
+		case ps := <-r.in:
+			for _, p := range ps {
 				r.handleIn(p)
+			}
 		case info := <-r.core.dht.peers:
 			r.core.dht.insertPeer(info)
 		case <-r.reset:

src/yggdrasil/stream.go

@@ -35,29 +35,19 @@ func (s *stream) init(rwc io.ReadWriteCloser) {
 }
 
 // writeMsg writes a message with stream padding, and is *not* thread safe.
-func (s *stream) writeMsg(bs []byte) (int, error) {
+func (s *stream) writeMsgs(bss [][]byte) (int, error) {
 	buf := s.outputBuffer[:0]
+	var written int
+	for _, bs := range bss {
 		buf = append(buf, streamMsg[:])
-	l := wire_put_uint64(uint64(len(bs)), util.GetBytes())
-	defer util.PutBytes(l)
-	buf = append(buf, l)
-	padLen := len(buf[0]) + len(buf[1])
+		buf = append(buf, wire_encode_uint64(uint64(len(bs))))
 		buf = append(buf, bs)
-	totalLen := padLen + len(bs)
+		written += len(bs)
+	}
 	s.outputBuffer = buf[:0] // So we can reuse the same underlying array later
-	var bn int
-	for bn < totalLen {
-		n, err := buf.WriteTo(s.rwc)
-		bn += int(n)
-		if err != nil {
-			l := bn - padLen
-			if l < 0 {
-				l = 0
-			}
-			return l, err
-		}
-	}
-	return len(bs), nil
+	_, err := buf.WriteTo(s.rwc)
+	// TODO only include number of bytes from bs *successfully* written?
+	return written, err
 }
 
 // readMsg reads a message from the stream, accounting for stream padding, and is *not* thread safe.

src/yggdrasil/switch.go

@@ -709,7 +709,7 @@ func (t *switchTable) handleIn(packet []byte, idle map[switchPort]time.Time) boo
 	if best != nil {
 		// Send to the best idle next hop
 		delete(idle, best.port)
-		best.sendPacket(packet)
+		best.sendPackets([][]byte{packet})
 		return true
 	}
 	// Didn't find anyone idle to send it to
@@ -812,7 +812,7 @@ func (t *switchTable) handleIdle(port switchPort) bool {
 			// Need to update the map, since buf was retrieved by value
 			t.queues.bufs[best] = buf
 		}
-		to.sendPacket(packet.bytes)
+		to.sendPackets([][]byte{packet.bytes})
 		return true
 	} else {
 		return false
@@ -826,7 +826,7 @@ func (t *switchTable) doWorker() {
 		// Keep sending packets to the router
 		self := t.core.peers.getPorts()[0]
 		for bs := range sendingToRouter {
-			self.sendPacket(bs)
+			self.sendPackets([][]byte{bs})
 		}
 	}()
 	go func() {